Blade grinding means



July 8, 1958 F. a. TAMMEN ETAL BLADE GRINDING MEANS 2 Sheets-Sheet 1 Filed April 18, 1956 INVENTORS F red B. Tammen- Author Mctz- BY {M w 1 W ATTORNEYS F. B. TAMMEN ET AL BLADE GRINDING MEANS July 8, 1958 2 Sheets-Sheet 2 Filed April 18, 1956 mm mm N N a 4 R w /m m y m M mm rn FA a L H United States Patent 2,841,932 BLADE GRINDING MEANS Fred B. Tammen and Anthony John Metz, Davenport,

Iowa, assignors to Bettendorf Bakery Equipment Company, Bettendorf, Iowa, a corporation of Iowa Application April 18, 1956, Serial No. 578,922 12 Claims. (Cl. 51-450) This invention relates to means for grinding endless slicer blades which are in place in a bread slicing machine.

Endless band blade bread slicing machines are commonly provided with vertically spaced pulleys over which the band blades run and between which the runs of each of the band blades cross. Intermediate the pulleys, one or more transverse rows of blade guides are provided for holding the band blades in parallel planes and equally spaced apart in the slicing zone. Usually two vertically spaced rows of blade guides are provided, one above and the other below a slicing zone, so that the blades are held parallel and against relative lateral movements while passing through the bread. After a machine has been in use for some time, the blades are of different widths due to various degrees of wear and different times of replacement of the individual blades.

The means and methods heretofore provided for in situ sharpening of the blades have generally involved a considerable degree of skill. In particular, the art has not heretofore succeeded in providing sharpening means which can be used without any particular skill and which, at the same time, enables uniform results to be achieved on blades of different widths.

Slicer blades of the types to which the invention relates generally move at relatively slow speeds of several feet per second. This is not favorable to effective sharpening. The prior art has sought to improve sharpening action in this respect by employing a powered grinding wheel which is driven in a direction to oppose the direction of movement of the blade being sharpened. The provision of powered wheels which are positively indexed and positioned is prohibitively costly. Non-powered grinding wheels have also been considered. Uniform results cannot be attained with these devices, and they cause deleterious excessive wear insofar as they involve a skewed dragging relationship between the grinding surface and the blade and have theadditional disadvantage of further reducing therelative speed between the grinding surface and the blade insofar as the two interengage in nonskewed relation. They also tend to load and glaze with metal wastefrom the blades and must be frequently dressed. Frequently, the presence of excessive grindings requires that after each sharpening several loaves be cut and expended solely for the purpose of cleaning the blades. p

The present invention provides a sharpener which is quickly indexed and positively but floatingly positioned to accurately sharpen all the blades in a slicer machine. The invention is particularly advantageous in that uniform results are'achieved on all the blades despite their varying width, and the attainment of such uniform results does not involve the excessive abrasion and removal of material from relatively wide blades. Accordingly, blade life is prolong d.

The invention also provides grinding surface and abrading means which are not themselves power driven but which accomplish efficient sharpening without dirtying the blades, without loading up and glazing the grinding surfaces themselves, and Without deleteriously engaging the blades in skewing relationship.

The present invention allows both sides of each blade to be sharpened at once and at the correct angle.

These and other objects and advantages of the invention will become more fully apparent from the following description, by way of example, of a presently preferred embodiment of the invention. In the accompanying drawings:

Figure 1 is a fragmentary side elevation of a bread slicing machine showing the present example of. the invention in association with the frame and band blades of a bread slicing machine.

Figure 2 is a view taken from line 2-2 in Figure 1.

Figure 3 is a view on an enlarged scale taken from line 33 in Figure 2, but showing two positions: of the parts.

Figure 4 is a partially broken away view on an enlarged scale of certain of the elements shown in Figure 3.

Figure 5 is a view tak n on line 5-5 in Figure 4.

Figure 6 is a view taken on line 6-6 in Figure 4.

Figure 7 is a fragmentary view similar to the major portion of Figure 5 and showing the parts in a different position, certain of the parts being omitted for purposes of clarity.

Figure 8 is a view taken on line 88 in Figure 7.

Figure 9 is a view taken on line 9-9 in Figure 7.

Figure 10 is a view taken on line 10-10 in Figure 9.

Figure 11 is a detail of a sharpener block employed in the example of the invention described herein.

As shown in Figure l, the illustrated example of the invention may be employed in abread slicing machine having upper and lower spaced pulleys 12 which are supported by suitable frame members 10. The array of crossed band blades 11 associated with the machine are straightened and guided on each side of the cutting zone by suitable blade guides 13 and 14 which are located above and below the cutting zone, all as is conventional.

According to the invention, blade sharpening apparatus may be provided on the output side of the array and above the cutting zone, as shown in Figure 1. The illustrated form of the invention includes guide bracket supports 15 adjustably fixed to opposite frame members 10 by set screws 16. A guide bar bracket 17 extends from each guide bracket support 15 and is adjustably fixed thereto by a set screw 18. The guide bar brackets 17 receive a guide bar shaft 20. A guide bar stop 21 is mounted on one end of the shaft and is provided with an adjustable stop bolt 22. A notch 23 is formed in the shaft 20.

In the illustrated embodiment of the invention, there is provided a sharpener assembly base 25 which has legs 26 in which are formed re-entrant notches 27. Bolted at longitudinally outboard locations on the sharpener assembly base 25 are a pair of blade guide assemblies 30. Each blade guide assembly 30 includes a pair of guide blocks 31, which may be chrome-plated on their bearing surfaces. The blocks 31 are each backed by a guide block backing member 32. The lower portions of the blocks 31 are recessed, and within the recesses and between each pair of blocks is positioned an inner guide member 33 which has the form of a small block. The base portion of each blade guide assembly 3 0 comprises a guide block assembly body 34, from which a pair of the guide block backing members 32 integrally extend. A machine screw 35 anchors the outer end of each block 31 to its backing member 32. A longer machine screw 36 passes through each pair of blocks 31 and the associated inner guide member 33, has its head seated against one of the associated backing members 32, and is threadedly received in the other associated backing member 32. It will thus be seen that the blocks 31 may be easily replaced if desired. Each pair of blocks 31 defines a bladereceiving slot which is relatively wide at its mouth 37 and which tapers inwardly to a guiding portion 38, which is of constant width and comprises the major extent of the slot.

Slidably mounted atlongitudinally inboard locations on the sharpener assembly base are a pair of sharpener block assemblies 40. Each sharpener block assembly includes a sharpener block 41 which may comprise diamond grit (preferably of a size of the order of from 46 to 200 grain) embedded in a suitable binder, such as a metal matrix, the diamond and binder being formed as pads 50. Each pad 50 comprises an integral part of each sharpener block 41. The back of each block 41 is formed with a ridge or key 45 which is received in a corresponding slot in an associated sharpener block backing member 42, One end of each of the blocks 41 is anchored to its backing member 42 by a machine screw 49 which is in sloppy, threaded engagement with the block 41. The other end of each of the blocks 41 is positioned by a set screw 43. The angle of the bladeengaging surface of each pad 50 may be adjusted by loosening the associated screw 49, adjusting the associ atedset screw 43 and then retightening the screw 49. As best seen in Figure 11, the blade-engaging surface of each pad 50 is gently convex in lateral cross-section. As best seen in Figures 5, 7 and 10, the blade-engaging surfaces of the pads 50 face each other in offset relationship and slant towards each other at a shallow angle. This angle may be adjusted by changing the angle of the blade-engaging surface of each pad 50 by manipulation of the screws 43 and 49 as described above.

The base portion of each sharpener block assembly 40 comprises a sharpener block assembly body 44 from which one of the sharpener block backing members 42 integrally extends. Each sharpener block assembly body 44 has a ridge or projection 52 which slides in a corresponding groove in the associated blade guide assembly body 34. On its opposite side, each sharpener block assembly body 44 has a groove 53. The facing grooves 53 are closed by means of a pair of filler blocks 55, each associated with one of the bodies 44 and fixed thereto by a pair of press fitted pins 56. A tension spring 47 is positioned within the grooves 53 and between the filler blocks 55 and is fixed at either end to a pin 46. Each of the pins 46 is fixed to one of the bodies 44.

A cam follower 48 is mounted on each of the bodies 44 and projects into the base 25. Rotatably mounted on the base 25 is a cam shaft 61 which is provided at its outer end with a handle 62. A cam 63 is mounted on the cam shaft 61 and is most clearly seen in Figure 8. Opposed shoulders on the cam 63 are adapted to abut against a stop pin 64 which is fixed to the base 25.

The cam is provided with detent notches 65 which are adapted to receive a spring-loaded detcnt 66 upon engagement of one or the other of the cam shoulders with the stop pin 64. As may be seen most clearly in Figure 6, the parts are so related that when the cam followers 48 are opposite the lows on the cam 63 they are not in following contact with the cam because they are overridden by engagement of the pads 50 with the blade being sharpened. It will be noted that the pads 50 are free to float with respect to each other, subject to the constant bias of the spring 47 which urges the pads 50 together.

When the grinder is to be used, the sharpener head assembly is put on the guide bar 28 by interengaging the notch 23 and the notches 27 and sliding the sharpener along the bar to the desired position or positions. With the band blades running, at normal speed if desired, and with the cam 63 in the position shown in Figure 8, the sharpener is shifted from the dotted line position shown in Figure 3 to the solid line position shown in Figure 3, the bolt 22 having been adjusted to engage a frame member just as each band blade 11 is received to the proper depth in the slots 38 (preferably substantially seated against the lower guide members 33). The handle 62 is then turned to shift the cam 63 to the position shown in Figure 6. The pads 50 floatingly engage a blade 11 at a predetermined sharpening angle. It will be seen that this angle remains the same regardless of whether the particular blade 11 which is engaged is relatively wide or relatively narrow. It will also be seen that there is no skewed dragging relationship between the pads 55) and the band blade 11. The blade is sharpened at. the desired angle without excessive-removal of metal and without loading up of the pads or dirtying of the band blade. The handle 62 is then turned to shift the cam 63 and disengage the pads 50, the sharpenin; head is shifted wholly or partially back toward the dotted line position shown in Figure 3 and is then translated along the guide bar 20 to be positioned opposite another band blade 11. The sequence of sharpening operations is then repeated. When all the blades have been sharpened, the sharpener head may be removed from the guide bar 20 at the notch 23. The band blades may be immediately used for slicing without cleaning them with preliminary runs of bread loaves which have to be discarded.

The invention is not limited to the provisions of all the details of the example described above. The scope of the invention is defined in the following claims.

What is claimed is:

l. A grinder for a transverse array of endless blade bands of a bread slicing machine comprising shaft means extending transversely across the machine apposite the array of blade bands, a sharpener base mounted on said shaft and oscillatably and transversely slidably associated therewith, a pair of abrasive sharpener blocks on said base and facing each other in offset relationship with their blade-engaging surfaces slanting towards each other at shallow angles, blade engaging and guiding means on said base and located in outboard relation with respect to said sharpener blocks, means for mounting said sharpener blocks for rectilinear sliding backing-off movement away from each other and for opposite movement toward each other, spring means on said base urging said blocks toward each other, means on said base for overcoming said spring means and urging said blocks away from each other whereby substantially uniform grinding angles and conditions may be maintained despite variations in the widths of bands being ground.

2. A grinder for a transverse array of endless blade bands of a bread slicing machine comprising shaft means extending tranversely across the machine apposite the array of blade bands, a sharpener base mounted on said shaft and oscillatably and transversely slidably associated therewith, a pair of abrasive sharpener blocks on said base and facing each other in offset relationship with their blade-engaging surfaces slanting toward each other at shallow angles, a pair of blade engaging and guiding means on said base and located in outboard relation with respect to said sharpener blocks, means for mounting said sharpener blocks for rectilinear sliding backing-off movement away from each other and for opposite movement toward each other, tensionedspring means coupling said blocks and urging said blocks toward each other, means on said base for overcoming said spring means and urging said blocks away from each other whereby substantially uniform grinding angles and conditions may be maintained despite variations in the Widths of bands being ground.

3. A grinder for a transverse array of endless blade bands of a bread slicing machine comprising shaft means extending transversely across the machine apposite the array of blade bands, a sharpener base mounted on said shaft and oscillatably and transversely slidably associated therewith, a pair of abrasive sharpener blocks on said base and facing each other in offset relationship with their blade-engaging surfaces slanting toward each other at shallow angles, each of said blocks comprising diamond grit embedded in a binder, blade engaging and guiding means on said base and located in outboard relation with respect to said sharpener blocks, means for mount ing said sharpener blocks for rectilinear sliding backingoff movement away from each other and for opposite movement toward each other, spring means on said base urging said blocks toward each other, means on said base for overcoming said spring means and urging said blocks away from each other whereby substantially uniform grinding angles and conditions may be maintained despite variations in the widths of bands being ground.

4. A grinder for a transverse array of endless blade bands of a bread slicing machine comprising shaft means extending transversely across the machine apposite the array of blade bands, at sharpener base mounted on said shaft and oscillatably and transversely slidably associated therewith, a pair of abrasive sharpener blocks on said base and facing each other in offset relationship with their blade-engaging surfaces slanting toward each other at shallow angles, means associated with said blocks to adjust said shallow angles, blade engaging and guiding means on said base and located in outboard relation with respect to said sharpener blocks, means for mounting said sharpener blocks for rectilinear sliding backingoff movement away from each other and for opposite movement toward each other, spring means on said base urging said blocks toward each other, means on said base for overcoming said spring means and urging said blocks away from each other whereby uniform grinding angles and conditions may be maintained despite variations in the widths of bands being ground.

5. A grinder for a transverse array of endless blade bands of a bread slicing machine comprising shaft means extending transversely across the machine apposite the array of blade bands, a sharpener base mounted on said shaft and oscillatably and transversely slidably associated therewith, a pair of abrasive sharpener blocks on said base and facing each other in offset relationship with their blade-engaging surfaces slanting toward each other at shallow angles, said surfaces being gently convex in lateral cross-section, blade engaging and guiding means on said base and located in outboard relation with respect to said sharpener blocks, means for mounting said sharpener blocks for rectilinear sliding backing-off movement away from each other and for opposite movement toward each other, spring means on said base urging said blocks toward each other, means on said base for overcoming said spring means and urging said blocks away from each other whereby uniform grinding angles and conditions may be maintained despite variations in the widths of bands being ground.

6. A grinder for a transverse array of endless blade bands of a bread slicing machine comprising an oscillatable shaft extending transversely across the machine apposite the array of blade hands, a sharpener base keyed to said shaft and slidable thereon, a pair of abrasive sharpener blocks, a mounting means for each of said sharpener blocks, said mounting means being supported on said base for transverse sliding movement with respect thereto, spring means for urging said pair of mounting means in opposite directions of transverse sliding movement with respect to said base for urging said sharpener blocks together, cam means on said base for urging said pair of mounting means in directions of sliding movement opposed to the urging of said spring means for urging said sharpened blocks apart, a pair of blade engaging and guiding means on said base and located in outboard relation with respect to said sharpener blocks and with respect to said sharpener block mounting means, said sharpener blocks facing each other in offset relation with their blade-engaging surfaces slanting toward each other at shallow angles whereby uniform grinding 6 angles and conditions maybe maintained despite varia tions in the widths of bands being ground.

7. A grinder for a transverse array of endless blade bands of a bread slicing machine comprising an oscillatable shaft extending transversely across the machine apposite the array of blade bands, a sharpener base keyed to said shaft and slidable thereon, a pair of abrasive sharpener blocks, and a pair of mounting means for each of said sharpener blocks, said mounting means being supported on said base for transverse sliding movement with respect thereto, spring means for urging said pair of mounting means in opposite directions of transverse sliding movement with respect to said base for urging said sharpener blocks together, cam means on said base for urging said pair of mounting means in directions of sliding movement opposed to the urging of said spring means for urging said sharpener blocks apart, a pair of blade engaging and guiding means on said base and located in outboard relation with respect to said sharpener blocks and with respect to said sharpener block mounting means, stop means associated with said oscillatable shaft for stopping said shaft when said base is moved inwardly toward any one of said array of blades a distance sufficient to allow said sharpener blocks and said blade engaging and guiding means to be presented to said blade, said sharpener blocks facing each other in offset relation with their blade-engaging surfaces slanting toward each other at shallow angles, and said surfaces being gently convex in lateral cross-section whereby uniform grinding angles and conditions may be maintained despite variations in the widths of bands being ground.

8. A grinder for a transverse array of endless blade bands of a bread slicing machine comprising an oscillatable shaft extending transversely across the machine apposite the array of blade bands, a sharpener base keyed to said shaft and slidable thereon, a pair of abrasive sharpener blocks, a mounting means for each of said sharpener blocks, said mounting means being supported on said base for transverse sliding movement with respect thereto, spring means for urging said pair of mounting means in opposite directions of transverse sliding movement with respect to said base for urging said sharpener blocks together, cam means on said base for urging said pair of mounting means in directions of sliding movement opposed to the urging of said spring means for urging said sharpener blocks apart, a pair of blade engaging and guiding means on said base and located in outboard relation With respect to said sharpener blocks and with respect to said sharpener block mounting means, said sharpener blocks facing each other in offset relation with their blade-engaging surfaces slanting toward each other at shallow angles, and said surfaces being gently convex in lateral cross-section whereby uniform grinding angles and conditions may be maintained despite variations in the widths of bands being ground.

9. A grinder for transverse array of endless blade bands of a bread slicing machine comprising an osciilatable shaft extending transversely across the machine apposite the array of blade hands, a sharpener base keyed to said shaft and slidable thereon, a pair of abrasive sharpener blocks, a mounting means for each of said sharpener blocks, said mounting means being supported on said base for transverse sliding movement with respect thereto, spring means for urging said pair of mounting means in opposite directions of transverse sliding movement with respect to said base for urging said sharpener blocks together, cam means on said base for urging said pair of mounting means in directions of sliding movement opposed to the urging of said spring means for urging said sharpener blocks apart, a pair of blade engaging and guiding means on said base and located in outboard relation with respect to said sharpener blocks and with respect to said sharpener block mounting means, said sharpener blocks facing each other in offset relation with their blade-engaging surfaces slanting toward each other at shallow angles whereby uniform grinding angles and conditions may be maintained despite variations in the widths of bands being ground, and means associated with said blocks to adjust said shallow angles.

10. Agrinder for endless blade bands of a bread slicing machine comprising a sharpener base, a pair of abrasive sharpener blocks on said base and facing each other in offset relationship with their blade-engaging surfaces slanting towards each other at shallow angles, blade engaging and guiding means on said base and located in outboard relation with respect to said sharpener blocks, means for mounting said sharpener blocks for rectilinear sliding backing-off movement away from each other and for opposite movement toward each other, spring means on said base urging said blocks toward each other, means on said base for overcoming said spring means and urging said blocks away from each other, and means for mounting said base in position for operative association with the band blades of the bread slicing machine with which it is used.

11. A grinder for endless blade bands of a bread slicing machine comprising a sharpener base, a pair of abrasive sharpener blocks on said base and facing each other in offset relationship with their blade-engaging surfaces slanting toward each other at shallow angles, means associated with said blocks to adjust said shallow angles, blade engaging and guiding means on said base and located in outboard relation with respect to said sharpener blocks,

means for mounting said sharpener blocks for rectilinear sliding backing-oh movement away from each other and for opposite movement toward each other, spring means on said base urging said blocks toward each other, means on said base for overcoming said spring means and urging said blocks away from each other and means for mounting said base in position for operative association with the band blades of the bread slicing machine with which it is used.

12; A grinder for endless blade bands of a bread slicing machine comprising a sharpener base, a pair of abrasive sharpener blocks on said base and facing each other in offset relationship with their blade-engaging surfaces slanting towards each other at shallow angles, blade engaging and guiding means, means for mounting said sharpener blocks for rectilinear sliding backing-off movement away from each other and for opposite movement toward each other, spring means urging said blocks toward each other, means for overcoming said spring means and urging said blocks away from each other, and means for mounting said base in position for operative association with the band blades of the bread slicing machine with which it is used.

References Cited in the file of this patent UNITED STATES PATENTS 

